Audience members should be ready, “villain” and able to vote for how “Drood” will finish. Photo: Joan Marcus

You’d think a good musical could satisfy a theatergoer’s craving for entertainment. Some catchy songs, maybe a few dances, a bit of romance: Who could ask for anything more?

Rupert Holmes, that’s who. Instead of a regular show, the mastermind behind “The Mystery of Edwin Drood” — not to mention “The Pina Colada Song” — came up with a musical murder mystery and a killer gimmick: The audience votes for the culprit, and the ending is changed accordingly.

In other words, this is the poster child of high-concept tuners. So much so that it’s willing to stop dead in its tracks every night while the numbers are tallied — “a daring and perhaps dangerously democratic move,” as the narrator puts it.

“Drood,” which swept the Tonys in 1986, is now getting its first major revival. It’s a fine production, considering how tricky the piece is.

Based on Charles Dickens’ unfinished last novel, Holmes’ book is set up as a show-within-a-show. The conceit is that we’re watching a performance of “The Mystery of Edwin Drood” at London’s Music Hall Royale in 1895. The Studio 54 audience gets mock programs along with the regular Playbills, and the cast occasionally stalks the aisles for some vaudevillian mingling.

The Chairman (a mutton-chopped Jim Norton, late of “The Seafarer”) guides us through this hall of mirrors, pushing the action along and introducing the actors. And casting is key to this show: Holmes’ songs are serviceable at best, requiring hams willing to go over the top and beyond.

The biggest name here is Chita Rivera, in her first Broadway outing in seven years. She gets roaring ovations as Princess Puffer, “the underworld’s reigning monarch.” Perhaps she’ll let loose as the run goes on, but right now she seems a bit wan compared to her co-stars.

Chief among them is Stephanie J. Block (“9 to 5,” “The Boy From Oz”). As Alice Nutting, “London’s leading male impersonator,” she gets to play both Edwin Drood and “Man of Mystery” Dick Datchery. Proving she’s more than a belter, Block puffs out her chest and struts her stuff, and has come up with a hilarious walk for the stooped, bearded Datchery.

As befits a good melodrama — or operetta, since the show nods to Gilbert and Sullivan — “Drood” is packed with colorful villains and not-so-innocent heroines. Will Chase (TV’s “Smash”) plays to the rafters as a dastardly heel, while Andy Karl and Jessie Mueller glower in bronze makeup as a pair of scheming twins from Ceylon.

Meanwhile, Betsy Wolfe’s saucy, not-so-demure heroine is a crowd-pleaser. Singing beautifully and shamelessly flaunting her cleavage, she was voted the murderer the other night, by a landslide.

Director Scott Ellis could easily have pushed the pace into a gallop rather than a trot, and cranked up the zany-meter a notch or two. Still, for a show doing triple duty as musical, choose-your-own-ending mystery and time-travel device, “Drood” is jolly good fun.